The present invention relates to a sliding switch plate for selecting between two power receptacles and the application of power thereto. The invention further relates to a sliding cover for use with a portable battery pack in which accessibility and power to one of two different receptacles is controlled by movement of the cover.
Battery packs capable of delivering power to devices having differing power demands are well known. Such battery packs typically comprise a plurality of storage batteries, such as the lead acid type, and an electrical circuit for configuring the interconnection of the batteries so as to deliver the desired power. For example, battery packs can be configured to deliver either 12 VDC power or 24 VDC power in order to selectively power devices at either level.
In such battery packs, different receptacles are typically provided for each different voltage level that the pack is capable of delivering. In the above example, one receptacle may be provided to which devices intended to receive 12 VDC can be coupled, whereas a different receptacle would be provided for connection to devices intended to receive 24 VDC. Suitable receptacles for this purpose are known in the art and typically have a unique configuration so that a device intended to receive 12 VDC can have a plug that uniquely mates to the 12 VDC receptacle while devices intended to receive 24 VDC have a plug uniquely adapted to fit only the-corresponding 24 VDC receptacle. In this manner, delivery of the proper voltage level is usually assured.
There are occasions, however, when even disparities in the physical dimensions of the receptacles are not sufficient to prevent a device from being plugged into the wrong receptacle. The operator may physically force the plug into the wrong receptacle or the device may have been rewired with a plug of the wrong size. In such instances, applying the incorrect voltage level could result in damage to either the device or battery pack or both. A need thus exists for providing safeguards to prevent incorrect connection of a device to be powered to the wrong power receptacle.
A further problem in using such multi-voltage battery packs relates to the need for internally switching to the correct power level. In the foregoing example, circuitry within the battery pack is typically provided so as to selectively configure the batteries to deliver the desired 12 VDC or 24 VDC. Such circuitry generally includes a switch that must be appropriately manipulated by the operator in order to select the desired voltage output. Even if the device is plugged into the appropriate power receptacle, failure to manually adjust such a switch may still cause damage to the device or to the battery pack. For example, the battery pack may deliver the wrong voltage level if not switched properly so that the device receives the incorrect voltage or the pack is subjected to excessive current demands.
Another problem presented by a battery pack having two receptacles is the possibility that devices will be plugged into both receptacles at the same time. This may result in excessive drain on the battery pack and, in those battery packs having internal fuses or circuit breakers, undesirable tripping of the circuit-protecting device may occur. This problem gives rise to a need for making only one receptacle available for use at a time, thereby avoiding possible use of both receptacles at the same time.
A need therefore exists for suitably controlling the circuitry within the battery pack so as to ensure appropriate selection of the voltage level corresponding to the chosen receptacle.